You are stranded on a leaky boat that is drifting toward shark-infested waters. Your primary radio is busted, but a backup is locked in a safe marked with the following: "When approaching shark-infested waters, unlock the safe using the isoelectric points of the peptide words."
The geniuses that set up the safe left you a hint (WHEN = 5).
You need to scramble your pH and amino acid knowledge to calculate the isoelectric points (round to the closest whole number) to unlock the safe and make the emergency call.
Hurry, the water is ankle deep and rising!